Function _mm256_mask_expand_ps
#[target_feature(enable = "avx512f", enable = "avx512vl")]
pub fn _mm256_mask_expand_ps(src: __m256, k: __mmask8, a: __m256) -> __m256Load contiguous active single-precision (32-bit) floating-point elements from a (those with their respective bit set in mask k), and store the results in dst using writemask k (elements are copied from src when the corresponding mask bit is not set).